Re: interp2d discussion

[jeremy theler <jeremy@talador.com.ar>]

Hi all,

I consider the addition of these routines to GSL as a major breakthrough.
Now I have three questions about generalization:

 1. can these 2D interpolation routines be extended to scattered (i.e. non-
rectangular) data?

 2. can these 2D interpolation routines be extended to n dimensions?

 3. both


Thank you for your hard work!

--
jeremy


On Friday 10 January 2014 09:37:04 Patrick Alken wrote:
> > Sure, that would be a reasonable option, but I'd like to do a bit of
> > research (i.e. ask a few more people for opinions) to see what solution
> > will be the least confusing. After all, if there is a change to be made,
> > this is the time to do it, not later after the code is incorporated into
> > GSL. I think backward compatibility will not be too much of a problem
> > because people will have to make other changes anyway to transition from
> > the interp2d_* functions to the corresponding gsl_* functions.
> 
> I think 2 additional functions could be added to help solve this issue
> and hide the indexing
> from the user:
> 
> interp2d_grid_set(double zarr[], size_t i, size_t j, double z)
> {
>    /* set point (i,j) of grid 'zarr' to value 'z' */
> }
> 
> and
> 
> interp2d_grid_fill(double zarr[], int (*grid_func)(double x, double y,
> void *params))
> {
>    /* fill entire grid 'zarr' using callback function 'grid_func'; this
> would be useful
>     * in cases where the user has a continuous/analytic function which
> is expensive to call, but
>     * they'd like to make a grid and then interpolate from it
>     */
> }